Well bit



Aug. 10, 1937. A. c. CATLAND Er' AL WELL BIT Filed Dec. 24, 1935 ALFRED C. CATLAND Mum/ h. M/IX WELL [NVE/VI'OES v /1,

A TI'OENEY Patented Aug. 1t), 1937 I UNITED STATES PATENT OFFICE wan. err

Application December 24, 1935, Serial N... 56,008 13 Claims. (01. 255-71) This invention relates to a well drillingtool and relates more particularly to a roller rock bit. A general object of this invention is to provide an improved simplified and particularly efii- 5 cient roller well drilling bit:

Another object of this invention is to provide a roller bit in which all of the. several cutters are carried by a single readily removable carrier whereby the bit may be easily and quickly re 10 conditioned by the replacement of the 'carrier and its cutters or by merely replacing the cutters following the removal of the carrier. bit of the present invention is adapted for use in'fields remote from repair shops and trans- 15 portation facilities because the cutters and the carrier for the cutters form a single compact unit that is easily transported and that may be quickly applied to the bit shank or head to recondition it for further use.

. Another object of this invention is to provide a well bit in which the cutters are supported by the carrier to be particularly rapid and efflcient in the drilling of a straight vertical bore.

Another object of thisinvention is to provide 25 a roller. bit of the character mentioned in which the cutter carrier may be easily removed from the head with simple tools and following theremoval of the carrier the cutters may be easily removed from the carrier topermit the individual 30 replacement of the cutters. Another object of this invention is to provide a roller bit of the character mentioned that embouies novel and very dependable means for securing the cutter carrier to the shank or head.

Another object of this inventionis to provide a roller rock bit that discharges the circulation 5 wall of-the well that assists in securing the cutter carrier to the head, definitely locatesthe carrier on the head and looks a cutter carrying pin' against displacement.

A further object of this invention is to pro- 50 vide a roller rock bit of the character mentioned that is simple and inexpensive to manufacture and repair. y The various objects and features of our invention will be fully understood from the following 55 detailed description of a typical" preferred form The welland application of the invention, throughout which description reference will be made to the accompanying drawing, in which:

-Fig. 1 is a side elevation of the bit provided by this invention with a portion broken away to appear in central vertical cross section. Fig. 2 is a central. vertical detailed sectional view of the bit taken in a plane at right angles to the plane of sectioning of Fig. 1. Fig. 3 is a bottom elevation of the shank or head with the cutter carrier removed. Fig. 4 is a bottom elevation of the bit and Fig. 5 is a top or plan view of the ters M on the carrier H.

The shank or head l constitutes the body of the bit'and is adapted to be connected with a drilling string to be operated or rotated in a well. The upper portion of the head I0 is pro- .vided with means for connecting with the drilling string while the lower portion of the head is shaped to receive the carrier I I.- In the typical form of the invention illustrated in the drawing; .a tapered screw threaded pin I is provided at the upper end of the head I 0 to facilitate the connection of the head .with the drilling string. Theintermediate or body portion of the head Ill maybe cylindrical. In accordance with the invention the shank or head is provided with two downwardly projecting legs IS. The legs l6 are preferably integral with the head Ill and are substantially diametrically opposite. The legs l6 project outwardly somewhat from the head 10 and their inner sides or surfaces H are inclined downwardly and outwardly. The invention provides a diametric slot or groove IS.

in the lower end of the head NJ. The groove l8 may extend from one side to the other of the head I 0 and its opposite ends are preferably spaced substantially 90 from the legs 3., The groove I8 is dovetailed having downwardly and inwardly inclined or convergent side walls. The upper wall of the groove I8 is flat and substantially normal to the vertical axis of the bit.

The carrier Ii is preferably, though not necessarily, an integral member and is disposed at the lower end of the head In to rotatably support the cutters l2, l3, and I l. The carrier II is a spider-like element including a transverse or substantially horizontal web l9 and three horizontally spaced projections A, B, and C projecting downwardly from the web l8. when the carrier II is secured to the head II) the web I9 is arranged below and is disposed longitudinally of the groove l8 so that the series of projections A, B, and C extends transversely or diametrically between the legs l6. In accordance with the invention a dove-tailed tongue 29 is provided on the upper side of the web I 9 to cooperate with the dove-tailed groove I8 in the head). The carrier II is arranged in position by introducing 10 the tongue 29 into the groove l8 and moving the carrier horizontally or transversely relative to the head Ill. The upper end of the dove-tailed tongue 20 is fiat and 'is adapted to cooperate with the upper wall of the groove l8 and one tapered side of the tongue is adapted to cooperate with in of the wedge 21 its opposite end portions which extend from opposite sides of the head l0 may be peened over to prevent loss or displacement of the wedge. When the tongue 20 is properly locked in the groove 48 its upper end bears against the upper wall of the groove and the upper side of the web I9 bears upwardly on the bottom 'of the 90 head "l as at 22. The tongue 20 dependably locked in the groove l9, as just described, securely and rigidly connects the carrier II with the head 19.

The projections A, B, and C constitute the cutter carrying parts of the carrier II. The projcction A ispreferably located at or adjacent one side of the central'vertical axis of the bit, the projection B is spaced outwardly from the projection A and is located at the same side of the said vertical axis as the projection A while the projection C is spaced outwardly from the projection A at the other side of the said ails. projection A-ls yoked or provided at its lower end I witha central notch 23 and two laterally projecting wings 24. The wings 24 have downwardly and outwardly inclined bearing surfaces 25 which oppose'andare substantially parallel with the inner surfaces ll of the legs I6. Pins 26 project outwardly from the bearing surfaces l1 and 25 and g0 tb'eirouter ends may bear on the surfaces 11 of the legs l6. Screws 9 may be passed outwardly through longitudinal openings 8 in the pins 26 and threaded into openings I in the legs l6 to connect the pins 26 with the legs. The screws 9 assistinattachingthecarrier ll tothehead ll. The projection B preferably has aflatv vertical inner side provided with a recessed bearing surface 2'I.'v The projection C is comparatively thick and may project outwardly beyond the peripheral go edge of the head II. The inner side of the pro-- jection C is preferably substantially vertical and is provided with a recessed bearing surface 23. 1 The inner cutters l2 and II are provided to act on and cut away the earth formation at the inner 5; portion of the bottom wall of the well. .The cutter I2 is rotatably mounted between the projections A and C while the cutter I3 is rotatably mounted between the projections A and B. The invention provides a single, simple means for io- 7 tatably supporting the two inner cutters l2 and I3. A removable pin 29 is introduced inwardly vthrough a substantially horizontal opening 36 in the leg Band has a reduced inner portion 3| threaded into an opening 32 in the projection 75 C. The threaded portion 3! of the pin being reside of the leg B. r

The cutter l2 which is rotatably supported on the pin 29 between the projections A and C is a frusto-conical cutter having a taperedperlphery provided with spacedcutting teeth 34. The cutter i2 is positioned with itssmall end facing the projection A. A roller bearing 35 may rotatably support the cutter l2 on the pin 29. A thrust washer 36 is arranged on the reduced portion 3| of the pin 29 between the'surface 28 of the projection C and the shoulder 33 of the pin. The washer 36 is adapted to receive outward thrusts from the end of the cutter l2. The thrust washer 36 has shouldered cooperation with the projection C at 31 which holds it against rotation. The cutter l2 rotatably mounted as just described projects downwardly below the projections A and C to act on the earth formation and follow an annular path immediately adjacent the center of v 29 in the space between the projections A and B.

The cutter I3 is frusto-conicaland is arranged with its small end .toward the projection A. Pe-

ripheral cutting parts 36 are provided on the cutter l3 and are adapted to project downwardly beyond the lower ends of the projections A and B to act on the formation at the bottom of the bore. A roller bearing 39 may rotatably support the cutter l3 on the pin 29. A thrust washer 40 is arranged on the pin 29 between the outer end of the cutter l3 and the bearing'surface 21 of the projection B. The washer 40 has shouldered engagement with the projection B at which holds it against turning on the pin 29. A spool or spacer 62 is provided on the pin 29 between the inner opposing ends of the cutters l2 and iii. The spacer 62 maintains the cutters l2 and'l3 in their proper'positions; and its opposite ends are adapted to receive inward thrustsfrom the cutters. In practice the spacer 62 passes through the notch 23 with freedom or clearance. The cutter l3 mounted as just described has an' an nular path of engagement with the earth formation which surrounds and overlaps that of the cutter l2. The cutters" l2 and I3 in being frusto- ,conical and in having their small ends facing inwardly form and act on a conical mound on 1 nor or small ends of the cutters I are adapted to bevelled or cut away to be substantially vertical asthey' come into engagement with the earth formation and thus properly cut the bore to a 2,089,486 gauge. The frusto-conicai cutters l4 rotating about downwardly and inwardly inclined axes follow annular paths surrounding and overlapping the path of the cutter l3 and their teeth 43 are substantially horizontal as they successivelyv come into cutting engagement with the' assists in securing the carrier H t'o'the"-h ea d 'Ill and definitely locates the carrier on the'head. A

15 central bore orv socket 49 extends downwardly in the head In from the upper end of the pin Ida-rid a passage or port vi) joins thelower end pf the socket. The projection C of the carrier H has a downwardly and outwardly inclined opening 20 5| which is longitudinally alignd-witliJtlieport 5|]. The opening 5| extends to the-flower end of the projection C and its lower pdr'tion, is enlarged providing a downwardly facing annular shoulder 52. The fluid discharge member-.48 is an elongate part passed through the opening 5!.

and having its upper end threaded into the lower portion of the port 50. The lower portion 68 of the member 48 is of enlarged diameter and is adapted to bear upwardly against theshoulder 30 52 when the member 4a is finally tightened into the port 59. The member 48 is provided with a central longitudinal fluid opening 53 whose upper end communicates with the ort 50.. A polygonal 1 socket 54 isprovided at the lower end of the 45 gagement of the enlargement 48 with the shoulder 52 may assist in securing the carrier ii to the head iii. In accordance with the invention the opening 32 receiving the threaded portion 3| of the pin 29 joins the lower enlarged part of the 50 opening 51. The inner end of the pin 29 is inclined and is shaped or grooved to be engaged by the 'enlarged portion 49 of the fluid dischar e member 48. This engagement of the portion 38* of the discharge member with the pin- 29 55 looks the pin 29 against unthreading. Thus the p the cutters l2, l3, and i4 or handled separately fluid' discharge member 48 serves to discharge the circulation fluid downwardly from a point immediately adjacent the bottom of the well,

definitely locates the carrier II with respect to the head l0, assists in securing the carrier to the head-and locks the cutter carrying pin 29 against rotation and unthreading.

The invention provides downwardly and outwardly inclined fluid ports 56 in the head it! 5 which extend downwardly fromthe socket 49 to discharge into the spaces between the legs IS and the projection A. The fluiddischarged from the ports 56 impinges against the outer cutters opening 53 to receive a wrench or the like for threadingthe member. The lower end of the.

and to discharge circulation fluid downwardly against the innercutters I2 and I3.

In operation the shank or head II is connec with the lower end of a drilling string which is to be rotated and fed downwardly in the well.

As the bit is rotated the inner cutters l2 and I .3 take annular paths across the inner portion of the bottom wall of the well while the outer cutters l4 pursue an annular course surrounding the path of the cutter I 3. The outer cutters I4 also act. on the side wall of the well to cut the well to gauge. Thus the cutters [2,13, and I4 act on substantially the entire bottom wall of the well. The frusto-conical inner cutters l2 and I3 operate against an inclined shoulder or shoulders of the earth formation and thus operate to center the bit in the well. The cutters l2, [Land I4 are dependably supported for independent rotation. The circuiation fluid discharged downwardly from the discharge member 48 adjacent the bottom wall of the well and adjacent the outer wall of the well isefiective in eroding the formation and producing the necessary turbulence in the bottom of the well. dove-tailed tongue 20 tightly wedged in the groove i8 by the wedge 2| dependably secures the carrier II to the head l0.

When it becomes necessary or 'desirable to replace the cutters l2; l3; or J4 or the carrier ll the tool iswithdrawn from the well and the carrier is removed from the head. To remove the carrier H from the head Ill one or both of the peened over ends of the gib. or wedge-2l are straightened out or cut ot! and the wedge 2| is driven from the groove la. The pins 9 are unthreaded from the openings 1 to free or disconnect the pins 28 from the legs IS. The fluid discharge member l8 is unthreaded from the .port 50 and removed whereupon the carrier ll may be moved transversely relative to the head ill to disengage its tongue 20 from the groove The.

i8. The removal of the member 48 from-the opening 5| permits the easy unthreading of'thecutter'carrylng pin 29 so that the cutters l2 and I3 may be easily removed from'the carrier ll.- Following'the removal of the carrier H from the head ill the outer cutters l4 may be readily slid from the pins 25. If found necessary a new or replacement carrier l0 provided with new cutters l2, l3, and I4 may be readllyassembled on the head "I. Where the carrier ll is not excessively worn it may be provided with new or replacement cutters l2, l3, and i4 and re-attached to the head id to condition the bit for further use. The carrier provided with from the cutters is a simple compact unit that may be easily transported for reconditioning the bit. 2 The fluid discharge member 49 may be replaced when it becomes worn or eroded through the action of the mud laden nuid.

Having described only a typical preferred form and application of our invention, we do notwish to be limited or restricted to the specific details herein set forth, but wish to reserve to' ourselves any variations o'r modifications that may apto those skilled in the art 01 within projections, and a tongue and groove connection between the head and carrier, the longitudinal axis of the tongue and groove of said connection being transverse of the head.

2. A well bitcomprising a head having spaced legs on its lower end, a carrier at the lower end of the head between the legs, roller cutters carried by the carrier, roller cutters rotatably supported between the legsand the projections, and a tongue and groove connection between the carrier and head, said connection comprising a diametric dove-tailed groove in the lower end of the head, and a dove-tailed tongue on the carrier introduced into the groove by relative transverse movement between the head and carrier.

3. A well bit comprising a head having spaced legs-projecting from its lower end, a carrier between the legs at the lower end of the head having projections on its lower end, a tongue and groove connection between the head and carrier, roller cutters, and means rotatably supporting the cutters between the legs and the projections.

4. A well bit comprising a headhaving spaced legs projecting from its lower end, a carrier between the legs at the lower end of the head having-projections on its lower end, a tongue and groove connection between the head and carrier.

screws connecting the projections and legs, and' roller cutters rotatably supported between the legs and projections.

5. A well bit comprising a head, a single carrier arranged diametrically across the lower end v,of the head, cutters on the carrier, a tongue-and groove connection between the head and carrier made up by relative transverse movement between the head and carrier, and a fluid discharge member cooperating with the head and carrier to hold them against relative transverse movement in both directions in the diametric A plane of the carrier.

6. A well bit comprising a head, a carrier at the lower end of the head, cutters on the carrier, a tongue and groove connection between the head and carrier made up by relative transverse movement between the head and carrier, there being a fluid port in the head and an opening in the carrier, and a fluid discharge member arranged in the port and opening to hold the head and carrier against relative transverse movement and conducting fluid from the port to discharge it from the carrier.

7. A well bit comprising a head having down-- wardly projecting legs, a carrier at the lower end of the headbetween the legs having projections extending toward, the legs, cutters rotatably supported between the legs and projections, a tongue and groove connection between the head and carrier made up by relative transverse movement between the head and carrier, and means connecting the legs and projections to prevent such relative transverse movement.

8. A well bit comprising a head having downwardly projecting legs, a carrier at the lower end of the head between the legs having projections extending toward the legs, cutters on the carrier, a tongue and groove connection between the head and carrier assembled by relative transversemovement between the head and carrier, and means detachably connecting the legs and projections to prevent such relative transverse movement.

9. A well bit including a head, a carrier at the lower end of the head, spaced legs on the lower end of the carrier having aligned openings, a pin passed through the opening of one leg and threaded into the opening of another leg, cutters supported by the pin, a tongue and groove connection between the head "and carrier assembled by relative transverse movement between the head and carrier, there being a fluid port in the head and an opening in said other leg registering with the port, and a fluid discharge member in the opening cooperating with the port'to receive fluid therefrom and to prevent relative transversev movement between the head and carrier, there being a fluid port in the head and an opening in the carrier aligned with the port, and a fluid dis charge member extending through the opening and threaded into the port to bear upwardly against the carrier to assist in securing the carrier to the head and to prevent relative transverse movement between the head and carrier.

11. A well bit including two elements, one a head, the other a cutter carrier, there being a dove-'tailed groove in one element, a dove-tailed tongue on the other element inserted in the groove by relative transverse movement between the elements to connect the elements, there being aligned openings in the elements, and a fluid discharge member threaded into one opening and cooperating with the other opening to lock the elements against relative transverse movement. 12. Awell bit comprising a head having a dovetailed groove in its lower end, legs projecting from the lower end of the head, a carrier, a dovetailed tongue on the carrier received in the groove to connect the carrier and head, spaced projecjecting from the lower end of the head, a carrier,

a dove-tailed tongue' on the carrier received in' the groove to connect the carrier and head, spaced projections on the carrier, pins on one of the projections extending outwardly to the legs, cutters rotatable on the pins, means connecting the pins and legs, a pin extending between and carried by the other projections, and roller cuttersgon said pin.

C. CATLAND. WILLIAM H. MAXWELL 

